Blender 2.79 How to Pin Down a Bone to a certain location?
Your best shot is using IK.

Give IK to the bone you'd like to stay fixed (make the chain as long as you
need).
Create a new bone close to the fixed one to become your
&quot;ground&quot;. This new bone MUST be a child of some bone higher in rank than the leg. If you have to, create a new &quot;master&quot; bone to be the parent of all bones.
Go back to the fixed bone's IK assign the new &quot;ground&quot; bone as the
target.


When you move the parent of the leg bones, the feet stay stuck to the ground.

Only when the feet need to move should you keyframe the &quot;ground bones&quot;.